This invention relates to a bumper of a motor vehicle which can be fastened on a part fixed to a vehicle, via at least one supporting element and by means of a screw connection, and has a foam energy absorber on which the at least one supporting element is mounted.
German Patent Document DE 29 12 178 C2 discloses a bumper design and support of this general type. In this arrangement, two supporting elements which are arranged at a distance one above the other and have a sharp-edged U-profile are embedded in the foam in the region in which the bumper is connected to the part fixed to the vehicle. The connecting region is relatively long and the thickness of the foam in the connecting region is very large because there is only a low possibility of energy absorption outside this region. The distance by which the bumper projects from the bodywork is thus relatively large and, in the case of high impact loading, it has to be expected that the sharp-edged supporting elements cause incisions in the compressing foam, as a result of which, after being relieved of the loading, the necessary quality of connection between the energy absorber and the supporting elements is no longer provided.
It is an object of the invention to ensure, in the case of a bumper which has a relatively small foam thickness and is supported over the length of the energy absorber on a part fixed to the vehicle, that, in the supporting region, the smallest possible reduction in energy-absorption capacity and good integration of the supporting element into the foam material, along with it being well secured against being torn out, are achieved, with the result that even forces with a high component in the transverse direction of the vehicle can be absorbed.
This object is achieved in preferred embodiments of the invention by providing a bumper assembly comprising a supporting element, a threaded connection projecting from the supporting element and serving to accommodate connecting of the supporting element to a fixed vehicle part, and a foam energy absorber mounted on the supporting element, wherein the supporting element is designed such that it is arched approximately in the form of an umbrella and reaches virtually over the entire height of the energy absorber, wherein the umbrella edge terminates relatively flatly and bears on the fixed vehicle part, and wherein supporting webs which are likewise supported on the part fixed to the vehicle project on the underside of the supporting element at a distance from the umbrella edge.
If the connecting webs are connected to one another and to the screw connection and to the umbrella edge by means of supporting walls, thus forming a honeycomb structure, then that region in the vicinity of the screw connection is additionally stiffened, while the flexibility towards the edge regions is hardly reduced, with the result that, in the event of being subjected to loading, no cracks arise in the foam material which reduce the extent to which the supporting element is secured against being torn out.
A distribution of the incident forces to be introduced and an even better integration are achieved if there are provided in the transverse direction of the bumper two supporting element portions which are connected to each other and the connection region of which is designed in an undulating manner, terminating flatly towards the nearby umbrella edge.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.